Experimental and theoretical study of magnetic and magnetocaloric properties of the lacunar La0.8□0.2MnO2.8 compound: Bean-Rodbell model

Abstract

In this paper, our research focuses on the correlation between structural and magnetic properties of the lacunar polycrystalline La0.8□0.2MnO2.8. The structural analysis proves a coexistence between R-3c and Pnma crystallographic structure. The analysis of the hysteresis loop shows that La0.8□0.2MnO2.8 sample is a Ferromagnetic soft material with an antiparallel magnetic coupled for both phases (Pnma and R-3c). Using servals theoretical approaches, the anisotropic parameters were estimated. The magnetocaloric properties were also investigated. A good result of the relative value of cooling power has been achieved (60% of that of Gd at 2 T) indicating that the material is a potential candidate for magnetic refrigeration application. The use of the Bean-Rodbell model based on the mean field theory allowed us to examine the nature of the magnetic transition and to calculate the magnetic and magnetocaloric properties with good accuracy. Moreover, within the framework of the mean-field theory, the spontaneous magnetization values MSp were estimated using the magnetic entropy change curves (-ΔS (M)).